This invention relates to an exhaust device for a small sized boat engine and more particularly to an improved arrangement for discharging and cooling the exhaust gases from an internal combustion engine, particularly when applied in a marine application.
In conjunction with the application of internal combustion engines for powering marine craft, it is a common practice to discharge at least a portion of the cooling water from the engine cooling jacket into the exhaust system so as to cool the exhaust and silence it. When this is done, it is possible to employ elastic joints in the exhaust system so as to permit some relative movement, absorb vibrations and avoid against undue stresses in the exhaust system. However, it has been found that the amount of cooling water discharged into the exhaust manifold may not be sufficient under all running conditions to cool the elastic joints adequately. If not cooled adequately, the joint can deteriorate with age with eventual failure.
It has, therefore, been proposed to provide a further arrangement for cooling the elastic joints. However, the type of cooling systems previously proposed have not truly been effective in providing adequate cooling for all parts of the elastic joint.
It is, therefore, a principle object of this invention to provide an improved arrangement for cooling an elastic joint in an internal combustion engine exhaust system.
It is a further object of this invention to provide an improved exhaust system for a small watercraft wherein the elastic joints in the system are adequately cooled under all conditions.